What a powerful beginning to the New Testament church, they were gathered together in one accord; that's when the Holy Spirit fell on them. There are two powerful truths in this short verse. First,they were joined together; Acts 2 says that they were in one accord. Spiritual outpourings are corporate events and happen to people who are moving together in God's kingdom. The second truth is this; they were in prayer. You join those two powerful ingredients together and an explosion is going to happen. Psalms says that this is the place of commanded blessing, when brothers and sisters dwell together in unity. Here are some comments from Andrew Murray about unity, prayer, and the necessity of the power of the Spirit in our church.

"Just before His ascension to heaven, Christ gave His final command with a promise attached to it. The command was that the disciples wait until the Holy Spirit was poured out. The promise was that they would receive power from the Holy Spirit to become His witnesses in all the furthest corners of the earth. For ten days the disciples pleaded for the promise to be fulfilled, then their prayers were answered. Likewise, wait upon the promise of the Holy Spirit until you receive it and then preach the gospel. Often churches today preach the gospel, but they forget about the promise of the Holy Spirit. Every believer should answer the call to pray for the gift of the Holy Spirit daily, as though speaking from one mouth and one heart. Many Christians pray only for themselves and forget to pray for the church of Christ. The power of the first disciples lay in the fact that they forgot about themselves and prayed as one body for the Holy Spirit to descend upon humanity."

David compared this to the oil being poured upon the high priest Aaron. He said the oil went down his beard to the edge of his robes. The anointing was essential for the high priest to perform his spiritual duties. In the same way, we need the oil poured on our heads, listen to David's description of what brings this about.

Psa. 133:1-3 ¶ Behold, how good and how pleasant it is For brethren to dwell together in unity! It is like the precious oil upon the head, Running down on the beard, The beard of Aaron, Running down on the edge of his garments. It is like the dew of Hermon, Descending upon the mountains of Zion; For there the LORD commanded the blessing— Life forevermore.

More Lord! Pour out your Spirit on us, pour out your Spirit on your church.